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John Dalton
Dalton formed the atomic theory , which has 5 parts. All mateer is composed of small particles called atoms, atoms of an element are identical unlike atoms of a different element, atoms cannot be subdivided created or destroyed, atoms of different elements combine in simple whole number ratios, and in chemical reactions, atoms are rearranged or seperated. -
Becquerel
Becquerel discovered radioactivity. He had been investigating Uranium and other radioaactive substances. -
J.J Thomson
J.J Thomson discovers the electron, using ccathrode ray. He discovers that the cathrode rays are made of a new charged particle, namely the electron. This is proven by the way the ray bends away from negative magnets, because they repel eachother. He then creates the plum pudding model based on this. -
Max Planck
Planck uses balck bodies, which absorb all electromagnetic radiation, to create the Planck's Postulate which describes the stablity of electrons and other subatomic particles E=hv. This stareted a debate over if objects are particles or wavelength. -
Robert Milikan
Robert Milikan discovers that the charge of the electron, which would be 1. -
Ernest Rutherford
Ernest Rutherford discovered that all the masses in the atom were in a small positively charged ball in the center of the atom, using his gold foil experiments. -
Rutherford Model
Thr Rutherford Model is made based on his experiments with gold foil and the his conclusion that the atoms had a nucleus. -
Neils Bohr
Bohr said that electrons move around the nucleus in incredibly large orbits. He presented the Bohr atomic model. -
J.J Thompson 2
Thompson discovers isotopes by putting ionized Neoon through an electric and magentic field. There were two different parabalas, and therefore, two different atomic masses. -
Louis de Brogile
Louis was studying the stability of the atom, using Planck. After studying both particles and wavelength and studied the wave and particle, and established wave-particle daulity of nature. This ended the debate which Planck. -
Werner Heisenberg
He discovered that many things about atoms can not be calculated. He found that it was impossible to determine where an electron would be at any given moment. So it was impossible to determine where the other subatomic particles would be. This is the uncertianity principle. -
Erwin Schrodinger
He came up with the quantum mechanical atomic model which shows the orbiting around the nucleus are in constant motion and are equidistant, but at different angles. It describes the functions of waves. -
Chadwick
James Chadwick discovered the neutron, which has a neutral charge. -
Otto Hahn
Ottto Hahn discovered nuclear fission, where the nucleas breaks up into two different nucli. He did this while using Uranium -
Democritus
Democritus says all matter is made up of atoms, which are so small they are invisible, and cannot be divided, and fill up the space they are in.
